Tri-directional break-away boom assembly

ABSTRACT

A break-away apparatus for a boom arm is positioned at a joint between a main boom portion and a boom tip to allow the boom tip to assume a neutral position and forward, rearward, and upward positions. First and second plates are disposed at the joint and a hinge assembly is positioned between the first and second plates. The hinge assembly includes a first ball joint; a first hinge pin; and a second hinge pin. The first and second plates are in a first position when the boom tip assumes the neutral position, and the first and second plates are movable with respect to each other about the first hinge axis, the second hinge axis, and a pivot point defined by the first ball joint. A first spring assists a return of the first and second plates to the first position.

RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 15/533,437, filed Jun. 6, 2017, now U.S. Pat. No. ______, whichclaims the benefit of U.S. Provisional Application No. 62/095,244,entitled TRI-DIRECTIONAL BREAK-AWAY BOOM ASSEMBLY and filed Dec. 22,2014, which is incorporated herein by reference.

BACKGROUND Field of Invention

A crop sprayer, often in the form of an agricultural vehicle, spraysfluid including herbicides, pesticides, and fertilizers on agriculturalcrops in a field. The fluid may be sprayed from nozzles mounted on aboom on the crop sprayer. Large agricultural sprayers typically havehorizontal booms to allow for extensive spray coverage of crops in afield with a single travel pass. In some cases, booms have a lengthbetween about 20 and about 150 feet.

Description of Related Art

With conventional crop sprayers, an operator may drive the crop sprayerforward in a field. As the crop sprayer moves in the field, the boom (ormore specifically, a boom tip) may impact an obstacle (such as a tree,power pole, fence or post, for example), or force may otherwise beapplied to the boom. This impact or force may damage the boom, the boomtip and/or the obstacle.

In some commercially produced chemical application booms, the boom tipsare configured to break away rearwardly as the sprayer moves forward.However, in some cases, such as when the sprayer travels backward, theboom encounters an obstacle wherein it is pushed forwardly. Moreover, anobstacle or other forces may push upwardly upon a boom tip. Many boomtips are not designed to break away forwardly or upwardly; thus, theboom may sustain extensive damage.

SUMMARY

In one aspect, the invention is directed to a break-away apparatus incombination with a boom arm of a vehicle, the boom arm having a mainboom portion and a boom tip. The apparatus is positioned at a jointbetween the main boom portion and the boom tip and allows the boom tipto assume a neutral position and to pivot to a forward position and to arearward position and to an upward position with respect to the mainboom portion. The apparatus has a first plate disposed at the joint, thefirst plate being attached to the main boom portion, and a second platedisposed at the joint, the second plate being attached to the boom tip.A breakaway hinge assembly is positioned between the first plate and thesecond plate. The breakaway hinge assembly has an upper joint having afirst ball joint, the upper joint connected to both the main boomportion and the boom tip.

The breakaway hinge assembly has a first hinge having a first hinge pinconnected to the first plate, the first hinge being pivotable about afirst hinge axis defined between the first ball joint and the firsthinge pin and a second hinge having a second hinge pin connected to thesecond plate, the second hinge being pivotable about a second hinge axisdefined between the first ball joint and the second hinge pin. The firstand second plates are in a first position with respect to each otherwhen the boom tip assumes the neutral position, and wherein the firstand second plates are movable with respect to each other about the firsthinge axis, the second hinge axis, and a pivot point defined by thefirst ball joint. A first spring generates a holding force to provide abreak away threshold, wherein the first and second plates are movablewith respect to each other when the threshold is exceeded, and whereinthe first spring assists a return of the first and second plates to thefirst position after the first and second plates move from the firstposition, A mid-joint is attached to the first plate, the mid-jointhaving a second ball joint, wherein the second ball joint is connectedto the first spring with an elongated rod, wherein horizontal andvertical movement of the elongated rod is accommodated at the mid jointby the ball joint.

A hinge connecting bar may connect the first hinge pin and the secondhinge pin and a first hinge seat attached to the second plate is shapedto receive a portion of the hinge connecting bar proximate the firsthinge pin, and a second hinge seat attached to the first plate is shapedto receive a portion of the hinge connecting bar proximate the secondhinge pin. The hinge assembly may further have a lever pivotally mountedto boom tip with a first pin connection and connecting the elongated rodto the first spring, wherein a first end of the first spring ispivotally mounted to the boom tip and a second end of the first springis pivotally mounted to the lever at a second pin connection to movewith lever. In one aspect, the lever has a triangular configuration withthe first pin connection, a second pin connection and a third pinconnection, with each of the three pin connections being pivotallymounted relative to the lever, wherein one end of the elongated rodconnects to the third pin connection to connect the first spring to thelever.

In another aspect, a break-away apparatus is disclosed for a boom armhaving a main boom portion and a boom tip. The apparatus is positionedat a joint between the main boom portion and the boom tip. The apparatusallows the boom tip to assume a neutral position and to pivot to aforward position and to a rearward position and to an upward positionwith respect to the main boom portion. The apparatus includes a firstplate disposed at the joint, a second plate disposed at the joint, and ahinge assembly positioned between the first plate and the second plate.The hinge assembly includes a first ball joint, a first hinge pinconnected to the first plate, a first hinge axis being defined betweenthe first ball joint and the first hinge pin, and a second hinge pinconnected to the second plate, a second hinge axis being defined betweenthe first ball joint and the second hinge pin. The first and secondplates are in a first position with respect to each other when the boomtip assumes the neutral position, and the first and second plates aremovable with respect to each other about the first hinge axis, thesecond hinge axis, and a pivot point defined by the first ball joint. Afirst spring generates a holding force to provide a break awaythreshold, wherein the first and second plates are movable with respectto each other when the threshold is exceeded. Further, the first springassists a return of the first and second plates to the first positionafter the first and second plates move from the first position. Thehinge assembly includes a second ball joint, wherein an elongated memberconnects the second ball joint and the first spring.

In another aspect, a method of using a break-away apparatus for a boomarm is disclosed. The boom arm comprises a main boom portion and a boomtip. The apparatus is positioned at a joint between the main boomportion and the boom tip. The apparatus allows the boom tip to assume aneutral position and to pivot to a forward position and to a rearwardposition and to an upward position with respect to the main boomportion. The apparatus comprises a first plate disposed at the joint; asecond plate disposed at the joint; and a hinge assembly positionedbetween the first plate and the second plate. The hinge assemblycomprises a first ball joint; a first hinge pin connected to the firstplate, a first hinge axis being defined between the first ball joint andthe first hinge pin; a second hinge pin connected to the second plate, asecond hinge axis being defined between the first ball joint and thesecond hinge pin; and a bar connecting the first hinge pin and thesecond hinge pin. The first and second plates are in a first positionwith respect to each other when the boom tip assumes the neutralposition. The method comprises moving the second plate away from thefirst plate so that the first and second plates are in a second positionwith respect to each other.

This summary is provided to introduce concepts in simplified form thatare further described below in the Detailed Description. This summary isnot intended to identify key features or essential features of thedisclosed or claimed subject matter and is not intended to describe eachdisclosed embodiment or every implementation of the disclosed or claimedsubject matter. Specifically, features disclosed herein with respect toone embodiment may be equally applicable to another. Further, thissummary is not intended to be used as an aid in determining the scope ofthe claimed subject matter. Many other novel advantages, features, andrelationships will become apparent as this description proceeds. Thefigures and the description that follow more particularly exemplifyillustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed subject matter will be further explained with reference tothe attached figures, wherein like structure or system elements arereferred to by like reference numerals throughout the several views.

FIG. 1 is a front perspective view of a crop sprayer with exemplary boomarms of the present disclosure.

FIG. 2 is a front perspective view of a single exemplary boom arm.

FIG. 3 is a front perspective view of an exemplary mid-boom section andboom tip of the boom arm of FIGS. 1 and 2.

FIG. 4 is a front perspective view of a joint between the mid-boomsection and the boom tip.

FIG. 5 is a front perspective view of the mid-boom section and boom tipof FIG. 3 in a rearward break configuration.

FIG. 6 is a front perspective view of a joint between the mid-boomsection and the boom tip in the rearward break configuration of FIG. 5.

FIG. 7 is a front perspective view of the mid-boom section and boom tipin a forward break configuration.

FIG. 8 is a front perspective view of a joint between the mid-boomsection and boom tip in the forward break configuration of FIG. 7.

FIG. 9 is a front perspective view of a joint between the mid-boomsection and the boom tip in an upward break configuration.

FIG. 10 is a bottom view of a joint between the mid-boom section and theboom tip in a neutral position, as depicted in FIGS. 1-4.

While the above-identified figures set forth one or more embodiments ofthe disclosed subject matter, other embodiments are also contemplated,as noted in the disclosure. In all cases, this disclosure presents thedisclosed subject matter by way of representation and not limitation. Itshould be understood that numerous other modifications and embodimentscan be devised by those skilled in the art which fall within the scopeand spirit of the principles of this disclosure.

The figures may not be drawn to scale. In particular, some features maybe enlarged relative to other features for clarity. Moreover, whereterms such as above, below, over, under, top, bottom, side, right, left,etc., are used, it is to be understood that they are used only for easeof understanding the description. It is contemplated that structures maybe oriented otherwise.

DETAILED DESCRIPTION

A break-away assembly of the present disclosure allows a boom tip tobreak away to the rear or front or upwardly of the agricultural vehiclewithout damaging the agricultural vehicle or the boom arm when the boomtip impacts an obstacle or when a sufficient force is otherwise appliedto the boom tip. Release of the boom tip diminishes the stress placed onthe boom arm and mounting apparatus.

A boom arm with a tri-directional boom-tip break-away feature isdescribed that can be used, for example, on liquid sprayers. A suitableliquid sprayer is disclosed in U.S. Patent Application Publication No.2012/0237284, assigned to AGCO Corporation, and entitled “Boom fore andaft breakaway assembly,” the disclosure of which is fully incorporatedby reference herein. Another suitable liquid sprayer is disclosed inU.S. Pat. No. 7,823,803, assigned to AGCO Corporation, and entitled“Integrated breakaway cylinder and method for constructing a boomassembly,” the disclosure of which is fully incorporated by referenceherein. A boom arm of the present disclosure may be attached to a liquidsprayer by conventional means.

An exemplary break-away boom arm of the present disclosure allows theboom tip to hinge backward, forward, or upward when coming in contactwith an obstruction in the field or when encountered by another obstacleor force. In one embodiment, the boom tip is connected to the main boomportion by a bi-directional hinge assembly and one or more ball socketjoints. In one exemplary embodiment, rebound of the boom tip is dampenedby a gas spring, which assists in bringing the boom tip back to centerfrom either forward or rearward movement. Moreover, rebound of the boomtip from an upward break due to gravity is dampened by the gas spring.

FIG. 1 shows a crop sprayer 100 having a tri-directional break-away boomassembly of the present disclosure. Crop sprayer 100 includes a frame102. Frame 102 may be of unitary construction or may include one or morepieces secured together. Typically, frame 102 includes a support thatspans the length of crop sprayer 100 and provides a structure formounting components of crop sprayer 100. Crop sprayer 100 generally alsoincludes a cab 104 mounted on frame 102. Cab 104 houses an operator andthe controls for crop sprayer 100.

An engine 106 may be mounted on a forward portion of frame 102 in frontof cab 104 or may be mounted on a rearward portion of frame 102 behindcab 104. Engine 106 is commercially available from a variety of sourcesand may include, for example, a diesel engine or a gasoline-poweredinternal combustion engine. Engine 106 provides a motive force to propelcrop sprayer 100 and also provides energy used to spray fluids from cropsprayer 100.

Frame 102 is supported by a pair of rear wheels 108 and a pair of frontwheels 110. Rear wheels 108 (and/or front wheels 110) may be driven byengine 106 so as to propel crop sprayer 100. In particular, engine 106may generate mechanical energy that may be transferred to rear wheels108 (and/or front wheels 110) by a transmission, drive shaft, and rear(and/or front) differential. Front wheels 110 (and/or rear wheels 108)may be operable to steer crop sprayer 100. The propulsion and directionof crop sprayer 100 may be controlled by one or more operator controlsthat include, but are not limited to, an accelerator, a brake, a controlhandle and a steering wheel 112.

Crop sprayer further includes a storage tank 114 for storing a fluid tobe sprayed on a field. The fluid may include chemicals, such as but notlimited to, herbicides, pesticides, or fertilizers. Storage tank 114 isusually mounted on frame 102, either in front of or behind cab 104. Cropsprayer 100 may include more than one storage tank 114 to storedifferent chemicals to be sprayed on the field. The stored chemicals maybe dispersed by crop sprayer 100 one at a time, or different chemicalsmay be mixed and dispersed together in a variety of mixtures.

Crop sprayer 100 further includes a pair of horizontally extending boomarms 11 that are operable to distribute the fluid over a wide swath inthe field. In an exemplary embodiment, each boom arm 11 is a trussassembly of aluminum pieces that supports a plurality of liquid spraynozzles (not shown). The plurality of nozzles may be spaced along boomarm 11; fluid is sprayed through the nozzles as crop sprayer 100 isdriven forward in direction T in the field to distribute the chemicalsonto crops in the field. Typically, an operator of crop sprayer 100 usesa control handle, located in cab 104, to control fluid dispersionthrough the nozzles of boom arm 11. In an exemplary embodiment, eachboom arm 11 includes boom tip 12, mid-boom section 14, and inner boomsection 16. In an exemplary embodiment, a breakaway assembly 20 ispositioned at a joint between boom tip 12 and mid-boom section 14.However, break-away assembly 20 may also be positioned at a jointbetween mid-boom section 14 and inner boom section 16 or elsewhere alongboom arm 11. In this discussion, the portion of boom arm 11 outward frombreak-away assembly 20 will be considered to be the “boom tip” and theportion of boom arm 11 inward from break-away assembly 20 (closer toframe 102) will be considered to be the “main boom portion.”

In FIGS. 2-10, only a single boom arm 11 is illustrated and discussed.However, it is to be understood that in an exemplary embodiment, theleft and right boom arms 11 shown in FIG. 1 are mirror images of eachother.

FIGS. 1-4 and 10 show views of horizontally extending boom arm 11 in aneutral position (i.e., with boom tip 12 not pivoted forward or backwardor upward). FIG. 4 is an enlarged view of the area surroundingbreak-away assembly 20. FIGS. 5 and 6 are full and partial perspectiveviews of mid-boom section 14 and boom tip 12 in a rearward breakconfiguration, relative to travel direction T shown in FIG. 1. FIGS. 7and 8 are full and partial perspective views of mid-boom section 14 andboom tip 12 in a forward break configuration. FIG. 9 is a partialperspective view of the break-away joint in an upward breakconfiguration.

As most easily seen in FIG. 6, in an exemplary embodiment, boom tip 12includes end plate 28, and mid-boom section 14 includes end plate 30.Hinge assembly 22 is positioned between end plates 28 and 30. While theterm “plate” is used, it is to be understood that plates 28 and 30 neednot be flat. On one side of the joint between main boom portion 14 andboom tip 12, end plate 28 is disposed at an end of boom tip 12. On theother side of the joint between main boom portion 14 and boom tip 12,end plate 30 is disposed at an end of main boom portion 14. End plates28, 30 are in a first position with respect to each other when the boomtip 12 assumes a neutral position relative to mid-boom section 14, asshown in FIGS. 1-4.

In an exemplary embodiment, break-away assembly 20 includes upper joint32, a first hinge 34, a second hinge 36, and mid-joint 72. In theillustrated embodiment, upper joint 32 is connected to both mid-boomsection 14 and boom tip 12; first hinge 34 is connected to plate 30; andsecond hinge 36 is connected to plate 28. Upper joint 32 may include,for example, a ball joint 38. Mid-joint 72 may include, for example, aball joint 80.

First hinge 34 and second hinge 36 are connected by hinge connecting bar40. The connection of first hinge 34 and second hinge 36 by hingeconnecting bar 40 forms a rigid structure that is able to withstandconsiderable forces. In an exemplary embodiment, first hinge 34 ismounted to plate 30 by bracket 42 and is removably seated in first seat44, which is mounted to plate 28. Second hinge 36 is mounted to plate 28by bracket 46 and is removably seated in second seat 48, which ismounted to plate 30.

In an exemplary embodiment, break-away assembly 20 allows boom tip 12 tobreak away to the rear or front of agricultural vehicle 100, or upward,without damaging boom arm 11 or boom tip 12 when boom tip 12 impacts anobstacle or when a sufficient force is otherwise be applied to boom tip12. The maximum angle that boom tip 12 may rotate may be limited by abackstop, the maximum compressibility of spring 50, or another feature.When boom tip 12 breaks away from mid-boom section 14 in a rearward (asshown in FIGS. 5 and 6) or forward (as shown in FIGS. 7 and 8) or upward(as shown in FIG. 9) direction in response to a first force, springs 50create a second force opposing and absorbing the force causing thebreaking away.

For example, as boom tip 12 breaks away from mid-boom section 14,springs 50 compress (compare the length of the springs 50 in thebreakaway configurations of FIGS. 6 and 8 and the neutral configurationof FIG. 4). Thus, the force causing boom tip 12 to break away transfersinto springs 50. When the force causing boom tip 12 to break away is nolonger present, boom tip 12 returns to its neutral position as shown inFIG. 4 by the compression pressure in springs 50. Primary functions ofthe springs 50 include maintaining the boom tip 12 in the neutralposition relative to mid-boom section 14 and returning the boom tip 12to the neutral position after breaking away. A spring constant of thesprings 50 generates a break-away threshold; when the threshold force onboom tip 12 has been exceeded, then boom tip 12 breaks away from theneutral position.

Springs 50 may also include a built-in dampening feature, such as in thecase where springs 50 are gas springs, so that break-away assembly 20does not slam shut when boom tip 12 returns back to its neutralposition. Two springs 50 are shown in the illustrated embodiment.However, it is contemplated that more or fewer springs can be used toprovide the desired pressure and dampening features.

As boom tip 12 breaks away from mid-boom section 14, end plates 28, 30move with respect to each other about first hinge axis 25 a (labeled inFIG. 4), second hinge axis 25 b, and/or a pivot point defined by balljoint 38. In an exemplary embodiment, at least one of first hinge seat44 and second hinge seat 48 releases from hinge connecting bar 40 inresponse to the first force causing boom tip 12 to break away. Which one(or both) of first hinge seat 44 and second hinge seat 48 releasesdepends upon the direction from which the force is coming. For example,as shown in FIGS. 5 and 6, a force coming from a front of crop sprayer100 causes first hinge seat 44 to release from hinge connecting bar 40.In this case, first hinge 34 remains attached to plate 30 while firstseat 44 remains attached to plate 28. Boom tip 12 pivots with respect tomid-boom section 14 along hinge axis 25 a (shown in FIG. 4) betweensecond hinge 36 and upper joint 32. In another example, as shown inFIGS. 7 and 8, a force coming from a rear of crop sprayer 100 causessecond hinge seat 48 to release from hinge connecting bar 40. In thiscase, second hinge 36 remains attached to plate 28 while second seat 48remains attached to plate 30. Boom tip 12 pivots with respect tomid-boom section 14 along hinge axis 25 b between first hinge 34 andupper joint 22. As shown in FIG. 9, with an upward break of boom tip 12,both first hinge 34 and second hinge 36 come out of their respectivefirst seat 44 and second seat 48.

As shown in FIGS. 6, 8 and 9, in an exemplary embodiment, each of firstseat 44 and second seat 48 is sized and shaped to fit snugly about hingeconnecting bar 40. For example, in the illustrated embodiment, hingeconnecting bar 40 is formed from a tube with a substantially squarecross-section. Thus, first seat 44 and second seat 48 each have aresilient insert 52 with a substantially square cut-out portion, asillustrated. When boom tip 12 is in the neutral position shown in FIGS.1-4, the flat sides of hinge connecting bar 40 mate with the resilientinsert 52 of each of first seat 44 and second seat 48. In an exemplaryembodiment, first seat 44 receives a portion of connecting bar 40proximate first hinge pin 34, and second seat 48 receives a portion ofconnecting bar 40 proximate second hinge pin 36.

In an exemplary embodiment, the hinge axes 25 a, 25 b of hinge assembly22 are not normal or perpendicular with respect to the bottom surface 24of boom arm 11 (which, when its associated sprayer 100 is disposed on ahorizontal surface, is also generally horizontal). Rather, as shown inFIG. 4, each hinge axis 25 a, 25 b of hinge assembly 22 is disposed atan acute angle alpha with respect to a line 26 that is perpendicular togenerally horizontally extending bottom surface 24 of boom arm 11. In anexemplary embodiment, alpha is between about 10 degrees and about 20degrees, and is most suitably about 15 degrees. Because of thisinclination, boom tip 12 becomes aligned slightly upward as well asforward (as shown in FIGS. 7 and 8) or rearward (as shown in FIGS. 5 and6) relative to mid-boom section 14 when pivoted on hinge axis 25 a or 25b. When the obstacle that caused the forward or rearward pivoting ofboom tip 12 relative to mid-boom section 14 is passed, gravity assistsin returning boom tip 12 to the neutral position shown in FIGS. 1-4.Other angles outside of the 10-20 degree range may be used, but smallerangles will not offer as much gravity assistance for the boom tip returnto its unpivoted position, and larger angles will result in additionalstresses on hinge assembly 22. While each of hinges axes 25 a, 25 b isillustrated as being angled from line 26 at the same angle alpha, it iscontemplated that in another embodiment, the hinge axes 25 a, 25 b canbe angled from line 26 at different acute angle.

In an exemplary embodiment, a first end of each gas spring 50 ispivotally mounted to boom tip 12 at pin 54. A second end of each spring50 is pivotally mounted to lever 56 at pin 58 to move with lever 56.Lever 56 is in turn pivotally mounted to boom tip 12 at pin 60. Thus,each gas spring 50 is mounted on boom tip 12 proximate end plate 28, onbracket 59 of upper truss member 61. While an exemplary location forsprings 50 is illustrated and described, it is contemplated that springs50 may also be positioned in another location while still serving togenerate a break away threshold force, serving to assist in returningthe boom tip 12 to the neutral position shown in FIGS. 1-4, anddampening such return motion.

In an exemplary embodiment, lever 56 has a triangular configuration inwhich first arm 62 connects pins 58 and 60; second arm 64 connects pins58 and 66; and third arm 68 connects pins 60 and 66. Each of pins 58, 60and 66 is pivotally mounted relative to lever 56. One end of anelongated member such as rod 70 passes through a bore in pin 66 toindirectly connect to springs 50 via lever 56. Another end of rod 70 isconnected to plate 30 at mid-joint 72. In an exemplary embodiment,mid-joint 72 is positioned approximately mid-way vertically (verticallymeaning parallel with line 26 in FIG. 4) between upper joint 32 andhinge assembly 22; mid-joint 72 is positioned approximately at the sameposition horizontally (horizontally meaning perpendicular to line 26 inFIG. 4) as upper joint 32; and mid-joint 72 is spaced away from endplate 30 by a greater distance than a distance between upper joint 32and end plate 30 (as shown in FIGS. 8 and 9).

As shown in FIG. 10, pin 74 surrounds a portion of rod 70 and alsopasses through pin 66. On the other side of pin 66, spring 76, which inan exemplary embodiment is a helical coil spring, surrounds a portion ofrod 70. Nuts 78 are tightened upon rod 70 outside of spring 76 and pin74 to secure rod 70 to lever 66. An opposite end of rod 70 is secured tomid-joint 72 at ball joint 80 (visible in FIG. 6). Upper joint 32 andmid-joint 72 are similarly configured, with ball joint 38, 80 held inplace by nuts 82 onto brackets 84, 86, 88, 90 which are in turn attachedto end plate 30.

As shown in the neutral position of boom arm 11 depicted in FIG. 4, pin66 of lever 56 is in its highest position. With either a rearward break,as shown in FIG. 6; or a forward break, as shown in FIG. 8; or an upwardbreak, as shown in FIG. 9, lever 56 swings down upon pivot pin 60because the breaking away of boom tip 12 increases a distance betweenpin 60 and mid-joint 72. This movement of lever 56 results incompression of springs 50. Horizontal and vertical movement of rod 70 isaccommodated at mid joint 72 by ball joint 80. At lever 56, a componentof the swiveling motion of rod 70 in a horizontal plane (i.e., parallelwith bottom surface 24 of boom arm 11) is accommodated by spring 76. Atlever 56, vertical motion of rod 70 is accommodated by pivoting of rod70 at pin 66. These structures allow for the swiveling movement of rod70 and spring 76 in three dimensions, so that rod 70 can transfer bothcompression and tension forces between mid-boom section 14 and boom tip12 without bending. By moving lever 56, rod 70 transfers the motion ofthe breaking away of boom tip 12 to springs 50 when rod 70 pulls uponlever 56 during the rearward, forward, or upward breaking away actions,as illustrated in FIGS. 6, 8 and 9.

From the rearward break configuration of FIG. 6, the forward breakconfiguration of FIG. 8, or the upward break configuration of FIG. 9, arebound back to the neutral configuration of FIG. 4 is dampened bysprings 50. Moreover, in an exemplary embodiment, compression spring 76(FIG. 10) reduces shocks. In a typical rebound, a settling back to theneutral position of FIGS. 1-4 involves some back and forth motion in allthree dimensions. Thus, the springs 50 and compression spring 76 smoothout such rebound and associated aftershocks.

In the illustrated embodiment, each spring 50 is a gas spring, such asone commercially available from SUSPA Incorporated of Grand Rapids,Mich. However, in other embodiments, the spring could be a compressioncoil spring or any other means of reacting to the changes in lengthcaused by rod 70 pulling and pushing upon lever 56. A spring with anappropriate spring constant can be selected depending on factors such asa mass, length and center of gravity of boom tip 12. Other factors thatcan be taken into consideration to determine an appropriate springconstant for keeping the boom tip 12 straight compared to the mid-boomsection 14 include factors such as field contour or acceleration needs,for example. With a lower spring constant, boom tip 12 breaks away moreeasily, while a higher spring constant results in a bottom tip 12 thatrequires higher forces to break away, thus generating a higher holdingforce. In an exemplary embodiment, the break-away motion is progressivein that the greater the angle of boom tip 12 away from the neutralposition, the less force is required to continue the break-away motion.Changing the spring pressure can be accomplished in a variety ofmanners. For example, one can physically exchange springs when higher orlower holding force is desired. In another example, springs withvariable or adjustable spring constants can be used.

While break-away assembly 20 has been described with reference to boomarm 11, it is contemplated that the described assembly can be used withother structures to provide for a tri-directional break-way mechanismthat automatically returns to a neutral position, with optionaldampening provided by a spring with an integrated damper function or aseparate damper.

Although the subject of this disclosure has been described withreference to several embodiments, workers skilled in the art willrecognize that changes may be made in form and detail without departingfrom the spirit and scope of the disclosure. While a particularconfiguration of break-away mechanism 20 is described, it iscontemplated that variations may be made. For example, while aparticular arrangement of elements is shown, it is contemplated thatparts of a break-away mechanism may be assembled otherwise. For example,while the illustrated embodiment shows a structure in which certainelements are attached to mid-boom section 14 and other elements areattached to boom tip 12, it is contemplated that these attachments maybe reversed or otherwise varied.

What is claimed is:
 1. A break-away apparatus in combination with a boomarm, the boom arm comprising a main boom portion and a boom tip, theapparatus being positioned at a joint between the main boom portion andthe boom tip, the apparatus allowing the boom tip to assume a neutralposition and to pivot to a forward position and to a rearward positionand to an upward position with respect to the main boom portion, theapparatus comprising: a first plate disposed at the joint, the firstplate being attached to the main boom portion; a second plate disposedat the joint, the second plate being attached to the boom tip; abreakaway hinge assembly positioned between the first plate and thesecond plate, the breakaway hinge assembly comprising: an upper jointcomprising a first ball joint, the upper joint connected to both themain boom portion and the boom tip; a mid-joint comprising a second balljoint, the mid-joint attached to the first plate, a first hingecomprising a first hinge pin connected to the first plate, the firsthinge being pivotable about a first hinge axis defined between the firstball joint and the first hinge pin; a second hinge comprising a secondhinge pin connected to the second plate, the second hinge beingpivotable about a second hinge axis defined between the first ball jointand the second hinge pin; a hinge connecting bar connecting the firsthinge pin and the second hinge pin; a first hinge seat attached to thesecond plate and shaped to receive a portion of the hinge connecting barproximate the first hinge pin; a second hinge seat attached to the firstplate and shaped to receive a portion of the hinge connecting barproximate the second hinge pin, wherein the first hinge seat and thesecond hinge seat have a resilient insert configured to fit snugly aboutthe hinge connecting bar such that when the boom tip is in the neutralposition the hinge connecting bar mates with the resilient insert ofeach of the first seat and the second seat; and a first spring thatgenerates a holding force to provide a break away threshold; wherein thefirst and second plates are in a first position with respect to eachother when the boom tip assumes the neutral position, and wherein thefirst and second plates are movable with respect to each other about thefirst hinge axis, the second hinge axis, and a pivot point defined bythe first ball joint when the threshold is exceeded, and wherein thefirst spring assists a return of the first and second plates to thefirst position after the first and second plates move from the firstposition, wherein the second ball joint is connected to the first springwith an elongated rod, wherein horizontal and vertical movement of theelongated rod is accommodated at the mid joint by the second ball joint.2. The combination of claim 1 wherein the first spring is a gas spring.3. The combination of claim 1 wherein a force coming from a front of theboom arm causes the first hinge seat to release from the hingeconnecting bar such that the boom tip pivots with respect to the mainboom portion about the second hinge axis, and wherein a force comingfrom a rear of the boom arm causes said second hinge seat to releasefrom the hinge connecting bar such that the boom tip pivots with respectto the main boom portion about the first hinge axis, and wherein a forcecoming from below the boom arm causes both the first and second hingeseats to release from the hinge connecting bar such that the boom tippivots about the first ball joint causing an upward break of the boomtip.
 4. The combination of claim 3 further comprising a lever pivotallymounted to said boom tip with a first pin connection and connecting theelongated rod to the first spring, wherein a first end of the firstspring is pivotally mounted to the boom tip and a second end of thefirst spring is pivotally mounted to the lever at a second pinconnection to move with the lever.
 5. The combination of claim 4 whereinthe lever has a triangular configuration with the first pin connection,the second pin connection and a third pin connection, with each of thethree pin connections being pivotally mounted relative to the lever,wherein one end of the elongated rod connects to the third pinconnection to connect the first spring to the lever.
 6. The combinationof claim 5 wherein the lever swings down upon the first pin connectionwhen the boom tip moves away from the neutral position because thebreaking away of boom tip increases a distance between the first pinconnection and the mid-joint, wherein such movement of the lever resultsin compression of the first spring.
 7. The combination of claim 6further comprising a second spring located proximate the third pinconnection between the elongated rod and the lever.
 8. The combinationof claim 7 wherein the second spring is a helical coil springsurrounding a portion of the elongated rod.
 9. The combination of claim1 further comprising a lever, wherein the lever has a first portionconnecting the lever and the boom tip, a second portion connecting thelever and the first spring, and a third portion connecting the lever andthe elongated member.
 10. The combination of claim 9 wherein the firstspring has first and second ends, and wherein the first end is pivotallyconnected to the boom tip, and wherein the second end is configured tomove with the lever.
 11. The combination of claim 1 wherein each of thefirst and second hinge axes is tilted at an acute angle relative to aline that is perpendicular to a bottom surface of the boom arm such thatthe boom tip pivots upwardly when it pivots forward or rearward.
 12. Abreak-away apparatus in combination with a boom arm, the boom armcomprising a main boom portion and a boom tip, the apparatus beingpositioned at a joint between the main boom portion and the boom tip,the apparatus allowing the boom tip to assume a neutral position and topivot to a forward position and to a rearward position and to an upwardposition with respect to the main boom portion, the apparatuscomprising: a first plate disposed at the joint, the first plate beingattached to the main boom portion; a second plate disposed at the joint,the second plate being attached to the boom tip; a breakaway hingeassembly positioned between the first plate and the second plate, thebreakaway hinge assembly comprising: an upper joint comprising a firstball joint, the upper joint connected to both the main boom portion andthe boom tip; a first hinge comprising a first hinge pin connected tothe first plate, the first hinge being pivotable about a first hingeaxis defined between the first ball joint and the first hinge pin; asecond hinge comprising a second hinge pin connected to the secondplate, the second hinge being pivotable about a second hinge axisdefined between the first ball joint and the second hinge pin; a hingeconnecting bar connecting the first hinge pin and the second hinge pin;wherein the first and second plates are in a first position with respectto each other when the boom tip assumes the neutral position, andwherein the first and second plates are movable with respect to eachother about the first hinge axis, the second hinge axis, and a pivotpoint defined by the first ball joint; a first spring that generates aholding force to provide a break away threshold, wherein the first andsecond plates are movable with respect to each other when the thresholdis exceeded, and wherein the first spring assists a return of the firstand second plates to the first position after the first and secondplates move from the first position; a mid-joint attached to the firstplate, the mid-joint comprising a second ball joint, wherein the secondball joint is connected to the first spring with an elongated rod,wherein horizontal and vertical movement of the elongated rod isaccommodated at the mid joint by the second ball joint; a first hingeseat attached to the second plate and shaped to receive a portion of thehinge connecting bar proximate the first hinge pin; a second hinge seatattached to the first plate and shaped to receive a portion of the hingeconnecting bar proximate the second hinge pin; and a lever pivotallymounted to said boom tip with a first pin connection and connecting theelongated rod to the first spring, wherein a first end of the firstspring is pivotally mounted to said boom tip and a second end of thefirst spring is pivotally mounted to the lever at a second pinconnection to move with the lever.